/******************************************************************************

Copyright (c) 2010, Cormac Flanagan (University of California, Santa Cruz)
                    and Stephen Freund (Williams College) 

All rights reserved.  

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.

    * Redistributions in binary form must reproduce the above
      copyright notice, this list of conditions and the following
      disclaimer in the documentation and/or other materials provided
      with the distribution.

    * Neither the names of the University of California, Santa Cruz
      and Williams College nor the names of its contributors may be
      used to endorse or promote products derived from this software
      without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

******************************************************************************/

// based on ASM code

/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2005 INRIA, France Telecom
 * All rights reserved.  
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package rr.instrument.analysis;

import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.Attribute;

/**
 * An abstract trace visitor.
 * 
 * @author Eric Bruneton
 */
public abstract class TraceAbstractVisitor extends AbstractVisitor {

    /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for internal
     * type names in bytecode notation.
     */
    public final static int INTERNAL_NAME = 0;

    /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for field
     * descriptors, formatted in bytecode notation
     */
    public final static int FIELD_DESCRIPTOR = 1;

    /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for field
     * signatures, formatted in bytecode notation
     */
    public final static int FIELD_SIGNATURE = 2;

    /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for method
     * descriptors, formatted in bytecode notation
     */
    public final static int METHOD_DESCRIPTOR = 3;

    /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for method
     * signatures, formatted in bytecode notation
     */
    public final static int METHOD_SIGNATURE = 4;

    /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for class
     * signatures, formatted in bytecode notation
     */
    public final static int CLASS_SIGNATURE = 5;

    /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for field or
     * method return value signatures, formatted in default Java notation
     * (non-bytecode)
     */
    public final static int TYPE_DECLARATION = 6;

    /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for class
     * signatures, formatted in default Java notation (non-bytecode)
     */
    public final static int CLASS_DECLARATION = 7;

    /**
     * Constant used in {@link #appendDescriptor appendDescriptor} for method
     * parameter signatures, formatted in default Java notation (non-bytecode)
     */
    public final static int PARAMETERS_DECLARATION = 8;

    /**
     * Tab for class members.
     */
    protected String tab = "  ";

    /**
     * Prints a disassembled view of the given annotation.
     * 
     * @param desc the class desc of the annotation class.
     * @param visible <tt>true</tt> if the annotation is visible at runtime.
     * @return a visitor to visit the annotation values.
     */
    public AnnotationVisitor visitAnnotation(
        final String desc,
        final boolean visible)
    {
        buf.setLength(0);
        buf.append(tab).append('@');
        appendDescriptor(FIELD_DESCRIPTOR, desc);
        buf.append('(');
        addText(buf.toString());
        TraceAnnotationVisitor tav = createTraceAnnotationVisitor();
        addText(visible ? ")\n" : ") // invisible\n");
        return tav;
    }

    /**
     * Prints a disassembled view of the given attribute.
     * 
     * @param attr an attribute.
     */
    public void visitAttribute(final Attribute attr) {
        buf.setLength(0);
        buf.append(tab).append("ATTRIBUTE ");
        appendDescriptor(-1, attr.type);

        if (attr instanceof Traceable) {
            ((Traceable) attr).trace(buf, null);
        } else {
            buf.append(" : unknown\n");
        }

        addText(buf.toString());
    }

    /**
     * Does nothing.
     */
    public void visitEnd() {
        // does nothing
    }

    // ------------------------------------------------------------------------
    // Utility methods
    // ------------------------------------------------------------------------

    protected TraceAnnotationVisitor createTraceAnnotationVisitor() {
        return new TraceAnnotationVisitor();
    }

    /**
     * Appends an internal name, a type desc or a type desc to
     * {@link #buf buf}.
     * 
     * @param type indicates if desc is an internal name, a field desc, a
     *        method desc, a class desc, ...
     * @param desc an internal name, type desc, or type desc. May be
     *        <tt>null</tt>.
     */
    protected void appendDescriptor(final int type, final String desc) {
        if (type == CLASS_SIGNATURE || type == FIELD_SIGNATURE
                || type == METHOD_SIGNATURE)
        {
            if (desc != null) {
                buf.append("// desc ").append(desc).append('\n');
            }
        } else {
            buf.append(desc);
        }
    }

}
